Lens module

ABSTRACT

A lens module includes a lens barrel having a top wall that has a bottom surface, and a lens group received by the lens barrel. The lens group includes a first lens adjacent to the top wall and a second lens attached to the first lens. A first complementary configuration is arranged between the first lens and the top wall of the lens barrel for ensuring a concentricity between the lens group and the lens barrel, and a second complementary configuration is arranged between the first lens and the second lens for ensuring a concentricity between the first lens and the second lens.

FIELD OF THE INVENTION

The present invention relates to a lens module with lens group, and moreparticularly, to a miniature lens module applicable to a camera moduleor a photographing module of a handheld device, such as a tabletcomputer, a mobile phone, or a personal digital assistant (PDA) and etc.

DESCRIPTION OF RELATED ART

With the rapid development of technologies, electronic devices havingimage pick-up functions, such as cameras, mobile phones, portablecomputers, tablets, are equipped with lens modules. For satisfying thedemands of high quality pictures, lens modules are designed andmanufactured with high precisions. As one of the key characters of alens module, concentricity is much important for performing high qualitypictures.

Generally, a lens module comprises a holder for receiving a plurality oflens group therein. The lens group should be provided with highconcentricity to be concentric with each other, and the combination ofthe lens group should be concentric with the holder. During actualmanufacturing process, the concentricity between the lens group, orbetween the lens group and the holder is difficult to be controlled.Thus, this disclosure provides a lens module provided with specialconfiguration for ensuring the concentricity thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiments can be better understood with referenceto the following drawings. The components in the drawings are notnecessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the present disclosure. Moreover,in the drawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is an illustrative cross-sectional view of a lens module inaccordance with an first exemplary embodiment of the present disclosure.

FIG. 2 is an illustrative cross-sectional view of a lens barrel of thelens module in FIG. 1.

FIG. 3 is an illustrative cross-sectional view of a first lens used inthe lens module in FIG. 1.

FIG. 4 is an illustrative cross-sectional view of the first lens in FIG.3 assembled with the lens barrel in FIG. 2.

FIG. 5 is an illustrative cross-sectional view of a second lens used inthe lens module in FIG. 1.

FIG. 6 is an illustrative cross-sectional view of the second lens inFIG. 5 stacked on the first lens in FIG. 3.

FIG. 7 is an illustrative cross-sectional view of a third lens used inthe lens module in FIG. 1.

FIG. 8 is an illustrative cross-sectional view of the third lens in FIG.7 stacked on the second lens in FIG. 5.

FIG. 9 is an illustrative cross-sectional view of a fourth lens used inthe lens module in FIG. 1.

FIG. 10 is an illustrative cross-sectional view of the fourth lens inFIG. 9 stacked on the third lens in FIG. 7.

FIG. 11 is an illustrative cross-sectional view of a lens module inaccordance with a second exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The present invention will hereinafter be described in detail withreference to exemplary embodiments. The first exemplary embodiment ofthe present disclosure provides a lens module that could be used in amobile phone, a tablet, or a digital camera. Referring to FIGS. 1 and 2,a lens module 100 comprises a lens barrel 90 and a lens group 10supported by the lens barrel 90. The lens group 10 has an optical axis6. The lens barrel 90 comprises a first holder 91, a second holder 92extending vertically from an edge of the first holder 91 and a receivingspace 7 formed by the first holder 91 and the second holder 92. In thisembodiment, the second holder 92 is integrated with the first holder 91.The first holder 91 comprises a top surface 911, a bottom surface 912opposed and parallel to the top surface 911, and a light aperture 13with a central axis 6′ drilled through the top surface 911 and thebottom surface 912 for passing lights into the lens barrel 90. Thebottom surface 912 of the first holder 91 has a first bottom surface 912surrounding the light aperture 13, a second bottom surface 912Bconnected with the second holder 92, and a first engaging portion 913connecting the first bottom surface 912A and the second bottom surface912B and surrounding the central axis 6′. So, the first bottom surface912A, the first engaging portion 913, and the second bottom surface 912Bare arranged sequentially from a center to a periphery. The secondholder 92 comprises an inner surface 921 jointing with and perpendicularto the bottom surface 912 of the first holder 91. The receiving space 7is formed by the inner surface 921 and the bottom surface 912cooperatively for receiving the lens group 10. The lens group 10comprises a first lens 1, a second lens 2 stacked on the first lens 1, athird lens 3 stacked on the second lens 2 and a fourth lens 4 stacked onthe third lens 3. The first lens 1 locates between the first holder 91and the second lens 2. The first lens 1, the second lens 2, the thirdlens 3 and the forth lens 4 are aligned sequentially along the opticalaxis 6.

Referring to FIGS. 1-4, the first lens 1 comprises a first object-sidesurface 11, an first image-side surface 12 opposed to the firstobject-side surface 11 and a first sidewall 13 connecting the firstobject-side surface 11 and the first image-side surface 12. The firstsidewall 13 at least partially abuts against the inner surface 921 ofthe second holder 92. The first lens 1 further has a first concaveportion 14 concave from the first image-side surface 12 towards thefirst object-side surface 11 and a second engaging portion 15 extendingfrom the first object-side surface 11 towards the first holder 91 andsurrounding the optical axis 6 for engaging with the first engagingportion 913. The first object-side surface 11 has a first opticalsurface 111 arranged in the middle thereof and centered about theoptical axis 6 for serving as an optical zone, a first connectingportion 112 connecting the first optical surface 111 and one end of thesecond engaging portion 15, and a second connecting portion 113connecting the other end of the second engaging portion 15 and the firstsidewall 13. When assembled, the first bottom surface 912A abuts againstthe first connecting portion 112, the second bottom surface 912B abutsagainst the second connecting portion 113, the first engaging portion913 abuts against the second engaging portion 15, and the first sidewall13 at least partially abuts against the inner surface 921 of the secondholder 92, thereby forming a first alignment precision for ensuring thecentral axis 6′ is coaxial with the optical axis 6 and the misalignmentbetween the lens group 10 and the lens barrel 90 can be prevented.Specially, the first engaging portion 913 and the second engagingportion 15 are configured to be a part of a circle, respectively So, theamount of the engagement between the first holder 91 and the first lens1 is four. In an alternative embodiment, the amount of the engagementbetween the first holder and the first lens may be less than four, suchas only the first engaging portion abuts against the second engagingportion, and the bottom surface and the sidewall are kept apredetermined distance from the first holder, thereby the firstalignment precision between the lens barrel and the lens group isdetermined solely by the engagement between the first engaging portionand the second engaging portion. The first engaging portion 913 is aconcave shape and the second engaging portion 15 is a convex shape formating the first engaging portion 913. Specially, outlines of the firstand second engaging portions 913, 15 are configured to be a part of acircle.

Referring to FIGS. 3-6, the second lens 2 comprises a second object-sidesurface 21, an second image-side surface 22 opposed to the secondobject-side surface 21 and a second sidewall 23 connecting the secondobject-side surface 21 and the second image-side surface 22. The secondsidewall 23 keeps a predetermined distance from the inner surface 921 ofthe second holder 92. The second lens 2 further has a first convexportion 24 extending from the second object-side surface 21 and awayfrom the second image-side surface 22 for engaging with the firstconcave portion 14 of the first lens 1 and a second concave portion 25concave from the second image-side surface 22 and towards the secondobject-side surface 21.

In this exemplary embodiment, the first concave portion 14 of the firstlens 1 and the first convex portion 24 of the second lens 2 define asecond alignment precision for holding the first lens 1 and the secondlens 2 in precisely coaxial relationship. When assembled, the firstimage-side surface 12 of the first lens 1 keeps a predetermined distancefrom the second object-side surface 21 of the second lens 2, thereby thesecond alignment precision is determined solely by the engagementbetween the first concave portion 14 of the first lens 1 and the firstconvex portion 24 of the second lens 2. The first concave portion 14 ofthe first lens 1 engaged with the first convex portion 24 of the secondlens 2 accordingly forms a first jointing surface 16. The first jointingsurface 16 has a first farthest curve 161 far away from the firstimage-side surface 12, a first outer part 162 extending from the firstfarthest curve 161 towards the second holder 92 and a first inner part163 extending from the first farthest curve 161 towards the optical axis6. The first outer part 162 and the first inner part 163 are symmetricalwith a plan 164 passed through the first farthest curve 161 and parallelto the optical axial 6. Optionally, a distance between the firstfarthest curve 161 and the first image-side surface 12 determines athickness of the first lens 1.

Referring to FIGS. 6-8, the third lens 3 comprises a third object-sidesurface 31, an third image-side surface 32 opposed to the thirdobject-side surface 31 and a third sidewall 33 connecting the thirdobject-side surface 31 and the third image-side surface 32. The thirdsidewall 33 keeps a predetermined distance from the inner surface 921 ofthe second holder 92. The third lens 3 further has a second convexportion 34 extending from the third object-side surface 31 and away fromthe third image-side surface 32 for engaging with the second concaveportion 25 of the second lens 2 and a third concave portion 35 concavefrom the third image-side surface 32 and towards the third object-sidesurface 31. In this exemplary embodiment, the second concave portion 25of the second lens 2 engages with the second convex portion 34 of thethird lens 3 accordingly forms a second jointing surface 26. The secondjointing surface 26 has a second farthest curve 261 far away from thesecond image-side surface 22, a second outer part 262 extending from thefirst farthest curve 261 towards the second holder 92 and a second innerpart 263 extending from the second farthest curve 261 towards theoptical axis 6.

Referring to FIGS. 7, 9 and 10, the fourth lens 4 comprises a fourthobject-side surface 41, an fourth image-side surface 42 opposed to thefourth object-side surface 41 and a fourth sidewall 43 connecting thefourth object-side surface 41 and the fourth image-side surface 42. Thefourth sidewall 43 abuts against the inner surface 921 of the secondholder 92 for ensuring the central axis 6′ is coaxial with the opticalaxis 6. The fourth lens 4 further has a third convex portion 44extending from the fourth object-side surface 41 and away from thefourth image-side surface 42 for engaging with the third concave portion35 of the third lens 3. In this exemplary embodiment, the third concaveportion 35 of the third lens 3 engages with the third convex portion 44of the fourth lens 4 accordingly forms a third jointing surface 36. Thethird jointing surface 36 has a third farthest curve 361 far away fromthe third image-side surface 32, a third outer part 362 extending fromthe third farthest curve 361 towards the second holder 92 and a thirdinner part 363 extending from the third farthest curve 361 towards theoptical axis 6.

Outlines of the concave portions 14, 25, 35 and the convex portions 24,34, 44 are respectively configured to be a part of a circle for ensuringthe concentricity between the lens group. In other words, the outlinesof the convex portions 14, 25, 35 and the concave portions 24, 34, 44are shaped as circular arc. The farther curves 161, 261, 361 are fartherfrom the corresponding image-side surface 12, 22, 32 than other portionof the jointing surfaces 16, 26, 36 for placing the outer parts 162,262, 362 and the inner part 163, 263, 363 on two sides of thecorresponding farther curves 16, 26, 36, respectively, thereby theconcentricity between the lens group is effectively enhanced, and themisalignment of the lens group 10 can be prevented.

Optionally, heights between the farthest curves 161, 261, 361 and thecorresponding image-side surfaces 12, 22, 32 can be changed according todifferent desires. The concave portions may be interchanged with thecorresponding first convex portions, such as the concave portionprovided on the first lens may be interchanged with the first convexportion provided on the second lens. As a result, the first concaveportion provided on the second lens and the first convex portion may beprovided on the first lens.

A second embodiment is similar to that of the first embodiment of thepresent invention except the shape of a first engaging portion of afirst holder and a second engaging portion of a first lens. Referring toFIG. 11, a lens module 100′ comprises a lens barrel 90′ with a centralaxis 6′ 61′ and a lens group 10′ with an optical axis 61 supported bythe lens barrel 90′. The lens group 10′ has a first lens 1′, a secondlens 2′ stacked on the first lens 1, a third lens 3′ stacked on thesecond lens 2′, and a fourth lens 4′ stacked on the third lens 3′. Thelens barrel 90′ has a first lens holder 91′ and a second holder 92′extending vertically from an edge of the first holder 91′. The firstholder 91′ has a first engaging portion 913′ with a bevel shaped and thefirst lens has a second engaging portion 15′ with a bevel shaped coupledwith the first engaging portion 913′. Optionally, the shape of the firstand second engaging portions may be in various as long as the firstengaging portion is shaped to match the second engaging portion forforming the first alignment precision to ensure the central axis 6′ 61′is coaxial with the optical axis 61.

The cooperation or engagement between the first lens with a first circleconcave portion and the second lens with a first circle convex portionfor ensuring the concentricity between the first lens and the secondlens when the first lens unit is stacked on the second lens unit, sothat the misalignment can be prevented.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present embodiment have been setforth in the foregoing description, together with details of thestructures and functions of the embodiment, the disclosure isillustrative only, and changes may be made in detail, especially inmatters of shape, size, and arrangement of parts within the principlesof the invention to the full extent indicated by the broad generalmeaning of the terms in which the appended claims are expressed.

What is claimed is:
 1. A lens module, comprising: a lens barrelcomprising a first holder, a second holder extending downwardly from thefirst holder, and a receiving space formed by the first holder and thesecond holder, the first holder having a light aperture with a centralaxis; and a lens group with an optical axis, comprising: a first lensabutting against the first holder for forming a first alignmentprecision for ensuring the central axis is coaxial with the optical axisand having a first object-side surface, a first image-side surfaceopposite to the first object-side surface, a first sidewall connectingthe first object-side surface and the first image-side surface, and afirst concave portion concave from the first image-side surface towardsthe first object-side surface; and a second lens stacked on the firstlens and having a second object-side surface facing the first image-sidesurface, a second image-side surface opposite to the second object-sidesurface, a second sidewall connecting the second object-side surface andthe second image-side surface, and a first convex portion extending fromthe second object-side surface and away from the second image-sidesurface for engaging with the first concave portion of the first lensfor forming a second alignment precision for ensuring the concentricitybetween the first lens and the second lens; wherein the first concavecoupled with the first convex forms a first jointing surface having afirst farthest curve far away from the first image-side surface, a firstouter part extending from the first farthest curve towards the secondholder and a first inner part extending from the first farthest curvetowards the optical axis; and the first concave portion of the firstlens and the first convex portion are configured to be a part of acircle, respectively; the first holder has a first bottom surfacesurrounding the light aperture, a second bottom surface and a firstengaging portion connecting the first bottom surface and the secondbottom surface and facing the receiving space and surrounding thecentral axis of the first holder and the first lens has a first abuttingportion abutting against the first bottom surface of the first holder, asecond abutting portion abutting against the second bottom surface ofthe first holder, a second engaging portion extending from the firstobject-side surface towards the first holder and coupled with the firstengaging portion, the second engaging portion connnecting the firstabutting portion and the second abutting portion, respectively; and thefirst engaging portion and the second engaging portion are configured tobe a part of a circle, respectively.
 2. The lens module as described inclaim 1 further comprising a third lens stacked on the second lens and afourth lens stacked on the third lens.
 3. The lens module as describedin claim 2, wherein the second lens further has a second concave portionand the third lens having a third object-side surface, a thirdimage-side surface opposite to the third object-side surface, and asecond convex portion extending from the third object-side surface awayfrom the third image-side surface for coupled with the second concaveportion, the second concave portion of the second lens and the secondconvex portion of the third lens are configured to be a part of acircle, respectively.
 4. The lens module as described in claim 3,wherein the third lens further has a third concave portion and thefourth lens having a fourth object-side surface, a fourth image-sidesurface opposite to the fourth object-side surface, and a third convexportion extending from the fourth object-side surface away from thefourth image-side surface for coupled with the third concave portion,the third concave portion of the third lens and the third convex portionof the fourth lens are configured to be a part of a circle,respectively.
 5. The lens module as described in claim 2, wherein thefirst concave portion provided on the first lens is interchanged withthe first convex provided on the second lens.
 6. The lens module asdescribed in claim 1, wherein the first engaging portion and the secondengaging portion are configured to be a bevel shaped, respectively.
 7. Alens module, comprising: a lens barrel comprising a first holder, asecond holder extending downwardly from the first holder and a receivingspace formed by the first holder and the second holder, the first holderhaving a light aperture with a central axis; and a lens group with anoptical axis, comprising: a first lens abutting against the first holderfor forming a first alignment precision for ensuring the central axis iscoaxial with the optical axis and having a first image-side surface faraway from the first holder; a second lens stacked on the first lens andhaving a second image-side surface far away from the first image-sidesurface; and a first complementary conformation defined between thefirst lens and the second lens and having a first jointing surfacehaving a first farthest curve far away from the first image-sidesurface, a first outer part extending from the first farthest curvetowards the second holder and a first inner part extending from thefirst farthest curve towards the optical axis; the first holder has afirst bottom surface surrounding the light aperture, a second bottomsurface and a first engaging portion connecting the first bottom surfaceand the second bottom surface and facing the receiving space andsurrounding the central axis of the first holder and the first lens hasa first abutting portion abutting against the first bottom surface ofthe first holder, a second abutting portion abutting against the secondbottom surface of the first holder, a second engaging portion extendingfrom the first object-side surface towards the first holder and coupledwith the first engaging portion, the second engaging portion connnectingthe first abutting portion and the second abutting portion,respectively; and the first engaging portion and the second engagingportion are configured to be a part of a circle, respectively.
 8. Thelens module as described in claim 7, wherein the first outer part andthe first inner part are configured to be a part of a circle,respectively.
 9. The lens module as described in claim 7, the firstouter part and the first inner part are symmetrical with a plan passedthrough the first farthest curve and parallel to the optical axial. 10.The lens module as described in claim 7 further comprising a third lensstacked on the second lens and a fourth lens stacked on the third lens,and the third lens has a third image-side surface far away from thesecond image-side surface.
 11. The lens module as described in claim 10further comprising a second complementary conformation defined betweenthe second lens and the third lens and having a second jointing surfacehaving a second farthest curve far away from the second image-sidesurface, a second outer part extending from the second farthest curvetowards the second holder and a second inner part extending from thesecond farthest curve towards the optical axis.
 12. The lens module asdescribed in claim 10 further comprising a third complementaryconformation defined between the third lens and the fourth lens andhaving a third jointing surface having a third farthest curve far awayfrom the third image-side surface, a third outer part extending from thethird farthest curve towards the second holder and a third inner partextending from the third farthest curve towards the optical axis. 13.The lens module as described in claim 7, wherein the first engagingportion and the second engaging portion are configured to be a bevelshaped, respectively.